TY - JOUR A1 - Bruecher, Martin A1 - Chakif, M’Barek A1 - Gurevich, Evgeny L. A1 - Hergenroeder, Roland T1 - Polydisperse NiTi nanoparticles investigated by X-ray standing waves and electron microscopy-A comparative study JF - Spectrochim. Acta B Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.sab.2014.05.004 SN - 0584-8547 VL - 98 SP - 60 EP - 64 ER - TY - JOUR A1 - Meyer, Cordula A1 - Demecz, Daniel A1 - Gurevich, Evgeny L. A1 - Marggraf, Ulrich A1 - Jestel, Guenter A1 - Franzke, Joachim T1 - Development of a novel dielectric barrier microhollow cathode discharge for gaseous atomic emission spectroscopy JF - J. An. At. Spectr. Y1 - 2012 U6 - http://dx.doi.org/10.1039/c2ja10225k SN - 0267-9477 VL - 27 SP - 677 EP - 681 ER - TY - JOUR A1 - Seemann, Ralf A1 - Brinkmann, Martin A1 - Herminghaus, Stephan A1 - Khare, Krishnacharya A1 - Law, Bruce M. A1 - McBride, Sean A1 - Kostourou, Konstantina A1 - Gurevich, Evgeny A1 - Bommer, Stefan A1 - Herrmann, Carsten A1 - Michler, Dominik T1 - Wetting morphologies and their transitions in grooved substrates JF - J. Phys.-Cond. Matter Y1 - 2011 U6 - http://dx.doi.org/10.1088/0953-8984/23/18/184108 SN - 0953-8984 VL - 23 SP - 184108 ER - TY - JOUR A1 - Hoppius, Jan S. A1 - Kukreja, Lalit M. A1 - Knyazeva, Marina A1 - Pöhl, Fabian A1 - Walther, Frank A1 - Ostendorf, Andreas A1 - Gurevich, Evgeny L. T1 - On femtosecond laser shock peening of stainless steel AISI 316 JF - Appl. Surf. Sci. Y1 - 2018 SN - 0169-4332 VL - 435 SP - 1120 EP - 1124 ER - TY - JOUR A1 - Pickhardt, Fritz A1 - Hoppius, Jan S. A1 - Gurevich, Evgeny L. T1 - Femtosecond laser shock peening of galvanized stainless steel JF - Procedia CIRP Y1 - 2018 VL - 74 SP - 320 EP - 323 ER - TY - JOUR A1 - Gurevich, Evgeny L. A1 - Levy, Yoann A1 - Gurevich, Svetlana V. A1 - Bulgakova, Nadezhda M. T1 - Role of the temperature dynamics in formation of nanopatterns upon single femtosecond laser pulses on gold JF - Phys. Rev. B Y1 - 2017 VL - 95 SP - 054305 ER - TY - JOUR A1 - Kanitz, Alexander A1 - Hoppius, Jan S. A1 - Mar Sanz, Maria A1 - Maicas, Marco A1 - Ostendorf, Andreas A1 - Gurevich, Evgeny L. T1 - Synthesis of Magnetic Nanoparticles by Ultrashort Pulsed Laser Ablation of Iron in Different Liquids JF - ChemPhysChem Y1 - 2017 U6 - http://dx.doi.org/10.1002/cphc.201601252 SN - 1439-7641 VL - 18 SP - 1155 EP - 1164 ER - TY - JOUR A1 - Maragkaki, Stella A1 - Elkalash, Abdallah A1 - Gurevich, Evgeny L. T1 - Orientation of ripples induced by ultrafast laser pulses on copper in different liquids JF - Appl. Phys. A Y1 - 2017 VL - 123 SP - 721 ER - TY - JOUR A1 - Guo, Qingchuan A1 - Ghadiri, Reza A1 - Weigel, Thomas A1 - Aumann, Andreas A1 - Gurevich, Evgeny L. A1 - Esen, Cemal A1 - Medenbach, Olaf A1 - Cheng, Wei A1 - Chichkov, Boris A1 - Ostendorf, Andreas T1 - Comparison of in Situ and ex Situ Methods for Synthesis of Two-Photon Polymerization Polymer Nanocomposites JF - Polymers Y1 - 2014 U6 - http://dx.doi.org/10.3390/polym6072037 SN - 2073-4360 VL - 6 SP - 2037 EP - 2050 ER - TY - JOUR A1 - Aumann, Andreas A1 - Ksouri, Sarah Isabelle A1 - Guo, Qingchuan A1 - Sure, Christian A1 - Gurevich, Evgeny L. A1 - Ostendorf, Andreas T1 - Resolution and aspect ratio in two-photon lithography of positive photoresist JF - J. Laser Appl. N2 - In this work, the authors report on investigations of two-photon lithography of positive photoresist. The dependency of the pattern linewidth on variation in the processing parameters, like the laser patterning velocity or power of the femtosecond laser oscillator, is presented. The influence of the scan velocity between 0.38 and 1.90 mm/s on the resolution is discussed for a layer thickness of 3.5 μm. By using a commercial positive photoresist, an aspect ratio of 5 has been realized for grid structures and the qualities of the produced structures are discussed. Y1 - 2014 U6 - http://dx.doi.org/10.2351/1.4857275 SN - 1042-346X VL - 26 SP - 022002 ER - TY - CHAP A1 - Ostendorf, Andreas A1 - Gurevich, Evgeny L. A1 - Shizhou, Xiao T1 - Fundamentals of Laser-Assisted Micro and Nanotechnologies: Selective Ablation of Thin Films by Pulsed Laser T2 - Fundamentals of Laser-Assisted Micro- and Nanotechnologies Y1 - 2014 SN - 978-3-319-05987-7 SP - 201 EP - 219 PB - Springer CY - Berlin ER - TY - JOUR A1 - Dobbelstein, Henrik A1 - Gurevich, Evgeny L. A1 - George, Easo P. A1 - Ostendorf, Andreas A1 - Laplanche, Guillaume T1 - Laser metal deposition of compositionally graded TiZrNbTa refractory high-entropy alloys using elemental powder blends JF - Additive Manufacturing Y1 - 2019 U6 - http://dx.doi.org/10.1016/j.addma.2018.10.042 SN - 2214-8604 VL - 25 SP - 252 EP - 262 ER - TY - JOUR A1 - Hoppius, Jan S. A1 - Maragkaki, Stella A1 - Kanitz, Alexander A1 - Gregorčič, Peter A1 - Gurevich, Evgeny L. T1 - Optimization of femtosecond laser processing in liquids JF - Appl. Surf. Sci. Y1 - 2019 U6 - http://dx.doi.org/10.1016/j.apsusc.2018.10.121 SN - 0169-4332 VL - 467-468 SP - 255 EP - 260 ER - TY - JOUR A1 - Kanitz, Alexander A1 - Förster, Daniel J. A1 - Hoppius, Jan S. A1 - Weber, Rudolf A1 - Ostendorf, Andreas A1 - Gurevich, Evgeny L. T1 - Pump-probe microscopy of femtosecond laser ablation in air and liquids JF - Appl. Surf. Sci. Y1 - 2019 SN - 0169-4332 VL - 475 SP - 204 EP - 210 ER - TY - JOUR A1 - Kasischke, Maren A1 - Subaşı, Ersoy A1 - Bock, Claudia A1 - Pham, Duy-Vu A1 - Gurevich, Evgeny L. A1 - Kunze, Ulrich A1 - Ostendorf, Andreas T1 - Femtosecond laser patterning of graphene electrodes for thin-film transistors JF - Appl. Surf. Sci. Y1 - 2019 SN - 0169-4332 VL - 478 SP - 299 EP - 303 ER - TY - JOUR A1 - Kiel, Frederik A1 - Bulgakova, Nadezhda M. A1 - Ostendorf, Andreas A1 - Gurevich, Evgeny L. T1 - Selective Delamination upon Femtosecond Laser Ablation of Ceramic Surfaces JF - Phys. Rev. Applied Y1 - 2019 U6 - http://dx.doi.org/10.1103/PhysRevApplied.11.024038 VL - 11 SP - 024038 ER - TY - JOUR A1 - Wang, Hao A1 - Pöhl, Fabian A1 - Yan, Kai A1 - Decker, Peer A1 - Gurevich, Evgeny L. A1 - Ostendorf, Andreas T1 - Effects of femtosecond laser shock peening in distilled water on the surface characterizations of NiTi shape memory alloy JF - Appl. Surf. Sci. Y1 - 2019 SN - 0169-4332 VL - 471 SP - 869 EP - 877 ER - TY - JOUR A1 - Zyla, Gordon A1 - Kovalev, Alexander A1 - Heisterkamp, Silas A1 - Esen, Cemal A1 - Gurevich, Evgeny L. A1 - Gorb, Stanislav A1 - Ostendorf, Andreas T1 - Biomimetic structural coloration with tunable degree of angle-independence generated by two-photon polymerization JF - Opt. Materials Express Y1 - 2019 VL - 9 SP - 2630 EP - 2639 ER - TY - JOUR A1 - Bialuschewski, Danny A1 - Hoppius, Jan S. A1 - Frohnhoven, Robert A1 - Deo, Meenal A1 - Gönüllü, Yakup A1 - Fischer, Thomas A1 - Gurevich, Evgeny L. A1 - Mathur, Sanjay T1 - Laser-Textured Metal Substrates as Photoanodes for Enhanced PEC Water Splitting Reactions JF - Adv. Eng. Materials Y1 - 2018 U6 - http://dx.doi.org/10.1002/adem.201800167 VL - 20 SP - 1800167 ER - TY - JOUR A1 - Dobbelstein, Henrik A1 - Gurevich, Evgeny L. A1 - George, Easo P. A1 - Ostendorf, Andreas A1 - Laplanche, Guillaume T1 - Laser metal deposition of a refractory TiZrNbHfTa high-entropy alloy JF - Additive Manufacturing KW - Additive manufacturing KW - High-entropy alloy KW - Laser metal deposition KW - Powder blend KW - Refractory Y1 - 2018 U6 - http://dx.doi.org/10.1016/j.addma.2018.10.008 SN - 2214-8604 VL - 24 SP - 386 EP - 390 PB - Fachhochschule Münster - University of Applied Sciences ER - TY - JOUR A1 - Hoppius, Jan S. A1 - Bialuschewski, Danny A1 - Mathur, Sanjay A1 - Ostendorf, Andreas A1 - Gurevich, Evgeny L. T1 - Femtosecond laser crystallization of amorphous titanium oxide thin films JF - Appl. Phys. Lett. Y1 - 2018 U6 - http://dx.doi.org/10.1063/1.5027899 VL - 113 SP - 071904 ER - TY - JOUR A1 - Levy, Yoann A1 - Derrien, Thibault J.-Y. A1 - Bulgakova, Nadezhda M. A1 - Gurevich, Evgeny L. A1 - Mocek, Tomáš T1 - Relaxation dynamics of femtosecond-laser-induced temperature modulation on the surfaces of metals and semiconductors JF - Appl. Surf. Sci. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.apsusc.2015.10.159 SN - 0169-4332 VL - 374 SP - 157 EP - 164 ER - TY - JOUR A1 - Majumdar, Jyotsna Dutta A1 - Gurevich, Evgeny L. A1 - Kumari, Renu A1 - Ostendorf, Andreas T1 - Investigation on femto-second laser irradiation assisted shock peening of medium carbon (0.4% C) steel JF - Appl. Surf. Sci. Y1 - 2016 SN - 0169-4332 VL - 364 SP - 133 EP - 140 ER - TY - JOUR A1 - Dobbelstein, Henrik A1 - Thiele, Magnus A1 - Gurevich, Evgeny L. A1 - George, Easo P. A1 - Ostendorf, Andreas T1 - Direct Metal Deposition of Refractory High Entropy Alloy MoNbTaW JF - Physics Procedia Y1 - 2016 VL - 83 SP - 624 EP - 633 ER - TY - JOUR A1 - Gurevich, Evgeny L. T1 - Mechanisms of femtosecond LIPSS formation induced by periodic surface temperature modulation JF - Appl. Surf. Sci. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.apsusc.2015.09.091 SN - 0169-4332 VL - 374 SP - 56 EP - 60 ER - TY - JOUR A1 - Zyla, Gordon A1 - Kovalev, Alexander A1 - Grafen, Markus A1 - Gurevich, Evgeny L. A1 - Esen, Cemal A1 - Ostendorf, Andreas A1 - Gorb, Stanislav T1 - Generation of bioinspired structural colors via two-photon polymerization JF - Scientific Reports Y1 - 2017 VL - 7 SP - 17622 ER - TY - JOUR A1 - Maragkaki, Stella A1 - Derrien, Thibault J.-Y. A1 - Levy, Yoann A1 - Bulgakova, Nadezhda M. A1 - Ostendorf, Andreas A1 - Gurevich, Evgeny L. T1 - Wavelength Dependence of Picosecond Laser-Induced Periodic Surface Structures on Copper JF - Appl. Surf. Sci. Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.apsusc.2017.02.068 SN - 0169-4332 VL - 417 SP - 88 EP - 92 ER - TY - CHAP A1 - Wang, Hao A1 - Gurevich, Evgeny L A1 - Ostendorf, Andreas T1 - Microhardness and microabrasion behaviour of NiTi shape memory alloy after femtosecond laser shock peening without coating in air T2 - High-Power Laser Materials Processing: Applications, Diagnostics, and Systems IX N2 - The experiment study presents the influence of femtosecond laser shock peening (FsLSP) without a protective layer in the air on the surface hardness and surface mechanical property of NiTi shape memory alloy. Femtosecond laser shock peening is a new possibility of direct laser ablation without any protective layer under atmospheric conditions, which can produce intense shock waves with low pulse energy in the air. The average surface roughness values of the NiTi alloy samples were measured, because the surface roughness may affect its friction resistance. The results showed that the surface roughness of NiTi increased after femtosecond laser shock peening treatment. In comparison with the initial state, the coefficient of friction decreased and surface microhardness increased after femtosecond laser shock peening treatment with different FsLSP parameters. This improvement of wear properties may be attributed to the enhancement of surface microhardness and surface titanium oxide layer induced by the shock wave and laser ablation during FsLSP treatment. Y1 - 2020 U6 - http://dx.doi.org/10.1117/12.2543550 SP - 1127301 EP - 1127301 PB - International Society for Optics and Photonics CY - USA ER - TY - JOUR A1 - Wang, Hao A1 - Jürgensen, Jens A1 - Decker, Peer A1 - Hu, Zhiyong A1 - Yan, Kai A1 - Gurevich, Evgeny L A1 - Ostendorf, Andreas T1 - Corrosion behavior of NiTi alloy subjected to femtosecond laser shock peening without protective coating in air environment JF - Applied Surface Science N2 - Laser shock peening with femtosecond laser was used to improve the corrosion resistance of biomedical NiTi alloy without protective coating in the air environment. The energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) based analysis showed that the laser ablation could produce titanium oxide layer and femtosecond laser shock peening (FsLSP) can generate residual stress in the surface layer of NiTi alloy. The FsLSP improved the corrosion resistance of NiTi in 3.5% NaCl solution and Hank’s solution and also prevented the formation of corrosion cracks and pits during corrosion testing. The reasons for the improvement of corrosion behavior may be the generation of residual stress and titanium oxide film during the laser surface treatment. KW - Laser shock peeningFemtosecond laserNiTi alloyCorrosion behaviorLaser surface treatment Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.apsusc.2019.144338 VL - 501/2020 SP - 144338 EP - 144338 ER - TY - JOUR A1 - Surkamp, N A1 - Zyla, G A1 - Gurevich, Evgeny L A1 - Klehr, A A1 - Knigge, A A1 - Ostendorf, Andreas A1 - Hofmann, MR T1 - Mode-locked diode laser-based two-photon polymerisation JF - Electronics Letters N2 - In this Letter, the authors present the construction of three-dimensional microstructures by two-photon polymerisation induced by ultrashort pulses of a mode-locked diode laser. The ultrafast light source is based on a diode laser with segmented metallisation to realise a waveguide integrated saturable absorber. It is subsequently amplified and compressed resulting in ultrashort laser pulses of 440 fs length and average output power of 160 mW at a fundamental repetition rate of 383.1 MHz. These pulses are coupled into a customised two-photon polymerisation setup. A series of suspended lines were fabricated between support cuboids for testing the process behaviour. A 3D structure with complex features was polymerised to demonstrate the high potential for mode-locked diode lasers in the field of direct laser writing. KW - laser mode locking; polymerisation; optical waveguides; high-speed optical techniques; two-photon processes; optical pulse compression; optical saturable absorption; integrated optics; semiconductor lasers Y1 - 2020 U6 - http://dx.doi.org/10.1049/el.2019.2385 SN - 0013-5194 VL - 56/2020 IS - 2 SP - 91 EP - 93 ER - TY - JOUR A1 - Maragkaki, Stella A1 - Skaradzinski, Christian A A1 - Nett, Ralf A1 - Gurevich, Evgeny L T1 - Influence of defects on structural colours generated by laser-induced ripples JF - Scientific Reports N2 - The colourisation of metallic surface which appears due to periodic surface patterns induced by ultrashort laser pulses is studied. Ripples due to the sub-micrometer size of their period act as a diffraction grating, generating structural colours. Carefully chosen strategy of the laser spot scanning allows us to mimic the nanostructures responsible for structural colours of some flowers on the metal substrate. We investigate the correlation between the colourising effects and the artificially-induced defects in the ripples structure and show that these defects can make the colours observable in a larger range of viewing angles. Further we address the influence of the processing parameters on the spectral profile of the reflected light. Y1 - 2020 U6 - http://dx.doi.org/10.1038/s41598-019-56638-x VL - 10 IS - 1 SP - 53 EP - 53 ER - TY - JOUR A1 - Wang, Hao A1 - Gurevich, Evgeny L A1 - Ostendorf, Andreas T1 - Femtosecond laser shock peening on the surface of NiTi shape memory alloy JF - Procedia CIRP N2 - Laser shock peening with a femtosecond laser system was presented in this research work. The NiTi shape memory alloy was processed by the femtosecond laser shock peening (FsLSP) treatment without a protective layer in the air. Femtosecond laser shock peening is a new surface technology, which can induce an intense shock wave with low single laser pulse energy under atmospheric conditions. The surface topography, roughness, microhardness, and wear resistance were measured on the surface of NiTi alloy before and after femtosecond laser peening treatment. The results showed that the surface roughness and microhardness could be increased after femtosecond laser shock peening, which may be due to the laser ablation and micro-plastic deformation induced by the shock wave. The wear property of NiTi alloy was improved, which may be attributed to the FsLSPed surface texturing and … KW - laser shock peeningfemtosecond laserNiTi alloymicrohardness Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.procir.2020.09.071 VL - 94/2020 SP - 910 EP - 913 ER - TY - JOUR A1 - Dobbelstein, Henrik A1 - George, Easo P A1 - Gurevich, Evgeny L A1 - Kostka, Aleksander A1 - Ostendorf, Andreas A1 - Laplanche, Guillaume T1 - Laser metal deposition of refractory high-entropy alloys for high-throughput synthesis and structure-property characterization JF - International Journal of Extreme Manufacturing N2 - Progress in materials development is often paced by the time required to produce and evaluate a large number of alloys with different chemical compositions. This applies especially to refractory high-entropy alloys (RHEAs), which are difficult to synthesize and process by conventional methods. To evaluate a possible way to accelerate the process, high-throughput laser metal deposition was used in this work to prepare a quinary RHEA, TiZrNbHfTa, as well as its quaternary and ternary subsystems by in-situ alloying of elemental powders. Compositionally graded variants of the quinary RHEA were also analyzed. Our results show that the influence of various parameters such as powder shape and purity, alloy composition, and especially the solidification range, on the processability, microstructure, porosity, and mechanical properties can be investigated rapidly. The strength of these alloys was mainly affected by the oxygen and nitrogen contents of the starting powders, while substitutional solid solution strengthening played a minor role. Y1 - 2021 UR - https://iopscience.iop.org/article/10.1088/2631-7990/abcca8/meta VL - 3 IS - 1 SP - 015201 EP - 015201 PB - IOP Publishing ER - TY - JOUR A1 - Syubaev, Sergey A1 - Gurbatov, Stanislav A1 - Modin, Evgeny A1 - Linklater, Denver P A1 - Juodkazis, Saulius A1 - Gurevich, Evgeny L A1 - Kuchmizhak, Aleksandr T1 - Laser Printing of Plasmonic Nanosponges JF - Nanomaterials N2 - Three-dimensional porous nanostructures made of noble metals represent novel class of nanomaterials promising for nonlinear nanooptics and sensors. Such nanostructures are typically fabricated using either reproducible yet time-consuming and costly multi-step lithography protocols or less reproducible chemical synthesis that involve liquid processing with toxic compounds. Here, we combined scalable nanosecond-laser ablation with advanced engineering of the chemical composition of thin substrate-supported Au films to produce nanobumps containing multiple nanopores inside. Most of the nanopores hidden beneath the nanobump surface can be further uncapped using gentle etching of the nanobumps by an Ar-ion beam to form functional 3D plasmonic nanosponges. The nanopores 10–150 nm in diameter were found to appear via laser-induced explosive evaporation/boiling and coalescence of the randomly arranged nucleation sites formed by nitrogen-rich areas of the Au films. Density of the nanopores can be controlled by the amount of the nitrogen in the Au films regulated in the process of their magnetron sputtering assisted with nitrogen-containing discharge gas. Y1 - 2020 UR - https://doi.org/10.3390/nano10122427 VL - 10 IS - 12 SP - 2427 EP - 2427 PB - Multidisciplinary Digital Publishing Institute ER - TY - JOUR A1 - Wang, Hao A1 - Keller, Sören A1 - Bai, Yongtao A1 - Kashaev, Nikolai A1 - Gurevich, Evgeny L A1 - Ostendorf, Andreas T1 - Laser shock peening on high-strength steel JF - SPIE.Digital Library N2 - High strength steel has been used in the aviation industry and automotive body structural applications to reduce its mass through a reduction in thickness. Therefore, it is very important to enhance its mechanical property, such as microhardness. In the present research, the high strength steel samples were treated by laser shock peening (LSP) with different laser pulse energy and laser pulse width. The microhardness and residual stress were measured to compare the difference between laser energy of 3 J with 10 ns and 5 J with 20 ns. The results in the study show that the surface LSP treatment can increase the microhardness and the compressive residual stress can be found when the samples were tested by hole drilling testing. Y1 - 2020 U6 - http://dx.doi.org/10.1117/12.2574988 VL - Volume 11546 IS - Proceedings Volume 11546 SP - 115460L EP - 115460L ER - TY - JOUR A1 - Elango, Kishore A1 - Hoppius, Jan S A1 - Kukreja, Lalit M A1 - Ostendorf, Andreas A1 - Gurevich, Evgeny L T1 - Studies on ultra-short pulsed laser shock peening of stainless-steel in different confinement media JF - Surface and Coatings Technology N2 - We investigate the role of liquid confinement media on ultra-short pulsed Laser Shock Peening (LSP). The LSP of stainless-steel 316 and 316 L was studied using Ti: Sapphire laser pulses of about 2 ps duration, maximum energy of about 1 mJ and pulse repetition rate of 5 kHz in different liquid confinement media of Ethanol, Deionized water and separate aqueous solutions of NaCl and Glycerol. It is found that the laser fluence and/or energy attenuating mechanisms like self-focusing, filamentation, plasma breakdown in the confinement media are less significant with ps laser pulses than those with sub-ps or fs pulse durations. It is shown that the resulting surface hardness of the peened steel as a function of laser fluence depends significantly on the confinement media and the relative increase in the hardness increases monotonically with the acoustic impedance of the liquid of the confinement medium used during … Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.surfcoat.2020.125988 VL - 397 SP - 125988 EP - 125988 ER - TY - JOUR A1 - Gurevich, Evgeny L A1 - Levy, Yoann A1 - Bulgakova, Nadezhda M T1 - Three-Step Description of Single-Pulse Formation of Laser-Induced Periodic Surface Structures on Metals JF - Nanomaterials N2 - Two different scenarios are usually invoked in the formation of femtosecond Laser-Induced Periodic Surface Structures (LIPSS), either “self-organization” mechanisms or a purely “plasmonic” approach. In this paper, a three-step model of formation of single-laser-shot LIPSS is summarized. It is based on the periodic perturbation of the electronic temperature followed by an amplification, for given spatial periods, of the modulation in the lattice temperature and a final possible relocation by hydrodynamic instabilities. An analytical theory of the evolution of the temperature inhomogeneities is reported and supported by numerical calculations on the examples of three different metals: Al, Au, and Mo. The criteria of the possibility of hydrodynamic instabilities are also discussed. Y1 - 2020 U6 - http://dx.doi.org/10.3390/nano10091836 VL - 10 IS - 9 SP - 1836 EP - 1836 ER - TY - JOUR A1 - Zyla, Gordon A1 - Kovalev, Alexander A1 - Gurevich, Evgeny L A1 - Esen, Cemal A1 - Liu, Ying A1 - Lu, Yongfeng A1 - Gorb, Stanislav A1 - Ostendorf, Andreas T1 - Structural colors with angle-insensitive optical properties generated by Morpho-inspired 2PP structures JF - Applied Physics A N2 - This paper describes how two-photon polymerization was used to generate biomimetic nanostructures with angle-insensitive coloration inspired by the blue butterflies of Morpho. Less angle dependence was achieved by engineering the structures with a certain degree of disorder, which delimited them from classical photonic crystals. Variations in the processing parameters enabled the color hue to be controlled. In this context, blue, green, yellow, and brown structures were demonstrated. Reflection spectra of the structures were simulated and studied experimentally in a broad range of incident angles. Additionally, a molding technique was performed as a potential scale-up strategy. The application of such biomimetic structures is discussed. Y1 - 2020 U6 - http://dx.doi.org/10.1007/s00339-020-03931-6 VL - 126 IS - 9 SP - 740 EP - 740 ER - TY - JOUR A1 - Zyla, Gordon A1 - Surkamp, Nils A1 - Gurevich, Evgeny L A1 - Esen, Cemal A1 - Klehr, Andreas A1 - Knigge, Andrea A1 - Hofmann, Matin R A1 - Ostendorf, Andreas T1 - Two-photon polymerization with diode lasers emitting ultrashort pulses with high repetition rate JF - Optics Letters N2 - In this Letter, we investigate the resolution of two-photon polymerization (2PP) with an amplified mode-locked external cavity diode laser with adjustable pulse length and a high repetition rate. The experimental results are analyzed with a newly developed 2PP model. Even with low pulse peak intensity, the produced structural dimensions are comparable to those generated by traditional 2PP laser sources. Thus, we show that a compact monolithic picosecond laser diode without amplification and with a repetition rate in the GHz regime can also be applied for 2PP. These results show the high application potential of compact mode-locked diode lasers for low-cost and compact 2PP systems. Y1 - 2020 U6 - http://dx.doi.org/10.1364/OL.401738 VL - 45 IS - 17 SP - 4827 EP - 4830 ER - TY - JOUR A1 - Wang, Hao A1 - Kalchev, Yordan A1 - Wang, Hongcai A1 - Yan, Kai A1 - Gurevich, Evgeny L A1 - Ostendorf, Andreas T1 - Surface modification of NiTi alloy by ultrashort pulsed laser shock peening JF - Surface and Coatings Technology N2 - This research paper presents the attempt at ultrashort pulsed laser shock peening with absence of absorptive layer and confining medium which could enhance surface microhardness and the abrasion property of NiTi shape memory alloy. The average roughness values of NiTi specimen were measured on the surface, because the roughness would affect the friction resistance. The microhardness and Young's modulus were investigated at different position of single laser spot by nanoindentation technique. The pin-on-plate sliding abrasion testing were performed with different load-force (0.5 N and 2 N) for different testing time. Results showed that ultrashort pulsed laser shock peening treatment would cause a significant improvement on friction coefficient and abrasion property, which was attributed to the change of surface modification, such as roughness, microhardness, microstructure and titanium oxide layer … Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.surfcoat.2020.125899 VL - 394 SP - 125899 EP - 125899 ER - TY - JOUR A1 - Wang, Hao A1 - Nett, Ralf A1 - Gurevich, Evgeny L A1 - Ostendorf, Andreas T1 - The Effect of Laser Nitriding on Surface Characteristics and Wear Resistance of NiTi Alloy with Low Power Fiber Laser JF - Applied Sciences N2 - The laser nitriding was performed in nitrogen gas at room temperature (20 °C) and low temperature (−190 °C) by a low power fiber laser to modify the wear and abrasion resistance of NiTi alloy. The surface roughness and element composition were analyzed by roughness device and energy-dispersive X-ray spectroscopy respectively. The results of roughness show that laser treatment can change the surface roughness due to the laser remelting. The effect of laser nitriding on the microhardness, friction coefficient, and worn scars of NiTi alloy was also studied, which shows that the microhardness of the NiTi alloy increases after laser nitriding. The optical microscope and scanning electron microscope were used to characterize the surface of NiTi alloy after wear testing to observe the microstructure of worn scars. The results show that the laser nitriding with different parameters can induce a nitride layer with different thicknesses and the higher energy deposition is the key factor for the formation of the nitride layer, which can decrease the friction coefficient and reduce wear loss during the application of NiTi alloy. The improvement of wear resistance can be attributed to the hard nitriding layer. KW - laser nitriding; wear resistance; NiTi alloy; roughness; microhardness Y1 - 2021 U6 - http://dx.doi.org/10.3390/app11020515 VL - 11 IS - 2 SP - 515 ER - TY - JOUR A1 - Kasischke, Maren A1 - Hartmann, Simon A1 - Niermann, Kevin A1 - Kostyrin, Denis A1 - Thiele, Uwe A1 - Gurevich, Evgeny L T1 - Pattern Formation in Slot-Die Coating JF - arXiv.org N2 - We experimentally study the occurrence of pattern formation during the slot-die coating of low-viscosity nearly Newtonian liquids onto Polyethylenterephthalat (PET)-substrates. In particular, it is demonstrated that with increase of the coating speed a homogeneous coating becomes unstable with respect to periodic stripe patterns. Thereby, depending on the liquid viscosity, the stripes can be oriented parallel or perpendicular with respect to the coating direction. Mixed states do also occur. The spatial period of perpendicular [parallel] stripes increases [decrease] with the coating speed. The dependence of the effect on various control parameters of slot-die coating is investigated. Finally, a simple theoretical model based on the hydrodynamics of thin films of partially wetting liquids is analysed. Comparing the results to the experiments, conclusions are drawn regarding the acting instability and pattern formation mechanisms. Y1 - 2021 UR - https://arxiv.org/abs/2101.01614 VL - 2021 SP - 1 EP - 24 ER - TY - CHAP A1 - Wang, Hao A1 - Gurevich, Evgeny L A1 - Ostendorf, Andreas T1 - Application of nanoindentation technique to test surface hardness and residual stress of NiTi alloy after femtosecond laser shock peening T2 - High-Power Laser Materials Processing: Applications, Diagnostics, and Systems X / SPIE.Digital.Library N2 - Laser shock peening is a new and important surface treatment technique that can enhance the mechanical properties of metal materials. Normally, the nanosecond laser with pulse-width between 5 ns and 20 ns is used to induce a high-pressure shock wave that can generate plastic deformation in the top layer of metals. The femtosecond laser shock peening in the air has been studied recently, which can induce higher pressure shock wave than that of traditional nanosecond laser shock peening in a very short time. The NiTi alloy is processed by femtosecond laser shock peening, then a nanoindentation device is used to measure its surface hardness and residual stress. The hardness results of NiTi alloy before and after treatment show that the femtosecond laser shock peening can increase the hardness of NiTi alloy, which also shows that the femtosecond laser can be used to perform laser shock peening on NiTi alloy without coating. Y1 - 2021 UR - https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11679/116790J/Application-of-nanoindentation-technique-to-test-surface-hardness-and-residual/10.1117/12.2593092.full?tab=ArticleLinkReference U6 - http://dx.doi.org/10.1117/12.2593092 SP - 116790J-0 EP - 116790J-5 PB - International Society for Optics and Photonics CY - USA ER - TY - JOUR A1 - Morawetz, Klaus A1 - Trinschek, Sarah A1 - Gurevich, Evgeny T1 - Interplay of viscosity and surface tension for ripple formation by laser melting JF - Physical Review B Y1 - 2022 U6 - http://dx.doi.org/10.1103/PhysRevB.105.035415 VL - 105 IS - 3 SP - 035415 ER - TY - JOUR A1 - Kiel, Frederik A1 - Trinschek, Sarah A1 - Kuchmizhak, Aleksandr A1 - Gurevich, Evgeny T1 - Colouration of diamond surfaces by laser-induced periodic surface structuring JF - Optics & Laser Technology Y1 - 2024 U6 - http://dx.doi.org/10.1016/j.optlastec.2023.109882 IS - 168 SP - 109882 ER -